http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49911
Richard Guenther <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2011.08.01 08:33:31
Ever Confirmed|0 |1
--- Comment #4 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-08-01
08:33:31 UTC ---
Ok, reproduced on a linux host. It's quite obvious:
void jsop_setelem(bool, int) (bool y, int z)
{
RegisterID SR.6;
<bb 2>:
if (y_1(D) != 0)
goto <bb 5>;
else
goto <bb 3>;
<bb 3>:
SR.6_11 = (RegisterID) z_3(D);
if (SR.6_11 <= 45)
the conversion truncates z_3 to precision 3, so it's not VRPs fault here.
It seems to be SRAs fault which replaces D.1809.offset_ with a register of
type RegisterID, then having to insert a not useless conversion (which it
should _never_ need - it's a sign of a bug):
D.1809.offset_ = z_3(D);
address.0_7 = (unsigned int) z_3(D);
if (address.0_7 <= 45)
D.1816_11 = (RegisterID) z_3(D);
^^^^^^^^^^^^^^ here
SR.6_6 = D.1816_11;
address.0_7 = (unsigned int) z_3(D);
if (address.0_7 <= 45)
Now, then comes along DOM and replaces
Optimizing statement address.0_7 = (unsigned int) z_3(D);
LKUP STMT address.0_7 = nop_expr z_3(D)
address.0_7 = (unsigned int) z_3(D);
FIND: SR.6_11
Replaced redundant expr '(unsigned int) z_3(D)' with 'SR.6_11'
==== ASGN address.0_7 = SR.6_11
Optimizing statement if (address.0_7 <= 45)
Replaced 'address.0_7' with variable 'SR.6_11'
for some other reason ...
